1. Field of the Invention
The present invention relates to a vehicular child seat detection system and, more specifically, relates to a vehicular child seat detection system for detecting whether or not a child seat has been laid on a front passenger seat.
2. Description of the Related Art
Conventionally, there is provided a vehicular child seat detection system for detecting whether or not a child seat has been laid on a front passenger seat. U.S. Pat. No. 5,690,356 discloses one such example.
As shown in FIGS. 14 and 15, a child seat 100 disclosed in this U.S. Patent has a seat bottom 102 that is fixed to frames 104, 106 for securing the seat bottom 102 to a vehicular seat. On the other hand, anchors 110, 120 and 130 are fixed to a frame member of a front passenger seat 150 of the vehicle. Lock clamps 112 and 114 are provided at respective ends of the frame 104, while lock clamps 116 and 118 are provided at respective ends of the frame 106. These lock clamps 112, 114, 116 and 118 allow the child seat 100 to be fastened to or released from the anchors of the vehicular seat. As shown in FIG. 15, the lock clamp 114, which receives the anchor 110, is composed of a movable bar 160, a top bar 162 and a spring 164. The movable bar 160 has a curved portion for locking engagement. The top bar 162 is formed at the end of the frame 104, and the movable bar 160 is rotatably fixed to the top bar 162 via a pivot shaft 168. The spring 164 urges pivotal rotation of the movable bar 160. In fastening the child seat 100 to the front passenger seat 150, the movable bar 160 is caused to rotate so as to receive the anchor 110 in the curved portion. In this manner, the child seat 100 is fastened to the front passenger seat 150.
On the other hand, an electrical switch 180 is provided contiguous to one of the anchors 110. As shown in FIG. 15, when the child seat 100 has been set properly with respect to the front passenger seat 150, the leading end of the top bar 162 presses a plunger 182 of the switch 180, which then outputs an ON-signal. In this manner, it is detected whether or not the child seat 100 is located suitably. Based on the detection result, other vehicular functional elements including a passenger restraint system such as an air bag device are controlled.
It is true that the vehicular child seat detection system of this type can detect whether or not the child seat 100 is located suitably. However, this system is incapable of detecting whether or not the lock clamps 112, 114, 116 and 118 of the child seat 100 have been securely fastened to the anchors 110, 120 and 130 of the vehicular seat. For example, a slight discrepancy in location between one of the lock clamps of the child seat and a corresponding one of the anchors of the vehicular seat may hinder secure attachment of the child seat to the vehicular seat. Such inconvenience may also be caused if the movable bar of the lock clamp does not move smoothly. The aforementioned system, which merely detects whether or not the child seat has been set in proper location, cannot detect whether or not the locking mechanism of the child seat has been securely fastened to the vehicular seat.
In view of the above-described background, the present invention aims at providing a vehicular child seat detection system capable of detecting whether or not the child seat has been securely mounted to the vehicular seat.
According to a first aspect of the present invention, there is provided a vehicular child seat detection system that includes a fixture bar and child seat detection means. Fixture attachments, which are integrally attached to a vehicular seat, are detachably coupled to the fixture bar. The fixture attachments extend from a child seat in a fore-to-aft direction thereof and are spaced apart from each other by a predetermined distance in the direction of the width of the child seat. The fixture attachments are provided with latches allowing the child seat to be fastened to or released from a vehicular seat. The child seat detection means detects whether or not the child seat has been mounted, based on movements of at least one of the latches resulting from coupling of the fixture attachments to the fixture bar.
Accordingly, in mounting the child seat to the vehicular seat, the child seat detection means detects, based on movements of at least one of the latches resulting from coupling of the fixture attachments to the fixture bar, whether or not the child seat has been securely fastened to the vehicular seat. Therefore, it is possible to determine whether or not the child seat has been firmly mounted to the vehicle.
In the first aspect of the present invention, the fixture attachments may be provided with groove portions in which the fixture bar is accommodated when the fixture attachments are coupled to the fixture bar. In this case, in coupling the child seat to the vehicular seat, the latches reduce an opening width of the groove portions so as to prevent the fixture bar from falling off the groove portions.
Furthermore, in the first aspect of the present invention, the fixture bar may hang across left and right seat frames of the vehicular seat.
The vehicular child seat detection system of the first aspect may be modified according to a second aspect of the present invention. In this case, the child seat detection means is composed of a rod and a switch. The rod is parallel to the fixture bar and longer than the distance between the fixture attachments. The switch is disposed substantially at a central portion of the rod and activated when a distance between the fixture bar and the rod becomes equal to or greater than a predetermined value due to the latches.
Accordingly, in mounting the child seat to the vehicular seat, if the fixture attachments for the child seat are coupled to the fixture bar hanging across the seat frames of the vehicular seat, the latches of the fixture attachments become sandwiched between the fixture bar and the rod and thus enlarge a space therebetween. Consequently, when the distance between the fixture bar and the rod becomes equal to or greater than the predetermined value, the switch is activated to detect whether or not the child seat has been mounted properly. Thus, with a simple structure, it is possible to detect whether or not the child seat has been mounted properly. Furthermore, the switch can be designed to be activated when the distance between the fixture bar and the rod reaches a value in the case where both the left and right fixture attachments engage the fixture bar. In this case, the use of one switch is sufficient to detect whether or not the child seat has been mounted properly.
The vehicular child seat detection system of the first aspect may be modified according to a third aspect of the present invention. In this case, the child seat detection means is set opposed to at least one of the left and right fixture attachments for the child seat. The child seat detection means is composed of a base body, moving means and a switch. The base body is attached to the fixture bar. The moving means is accommodated in the base body, pressed toward the fixture bar by urging means, and caused to move away from the fixture bar by at least one of the latches. The switch is activated due to a movement of the moving means.
Accordingly, in mounting the child seat to the vehicular seat, if the fixture attachments for the child seat are coupled to the fixture bar, the moving means, which is pressed towards the fixture bar, is caused to move away from the fixture bar by at least one of the latches of the fixture attachments. In response to this movement of the moving means, the switch is activated to detect whether or not the child seat has been mounted properly. Thus, with a simple structure, it is possible to detect whether or not the child seat has been mounted securely.
In the third aspect of the present invention, the moving means may be composed of a slider movably accommodated in the base body attached to the fixture bar. The slider may have an inclined plane for engagement with at least one of the latches.
The vehicular child seat detection system of the first aspect may be modified according to a fourth aspect of the present invention. In this case, the fixture bar hangs across left and right seat frames of the vehicular seat. The child seat detection means is composed of a rod, coupling means and strain measurement means. The rod is disposed parallel to the fixture bar and passes through engaging portions of the fixture attachments. The coupling means couples the rod to the fixture bar. The strain measurement means is attached to the rod.
Accordingly, in mounting the child seat to the vehicular seat, if the fixture attachments for the child seat are coupled to the fixture bar, the rod is strained. By measuring the amount of strain imposed on the rod by means of the strain measurement means, it is detected whether or not the child seat has been mounted properly. Thus, with a simple structure, it is possible to detect whether or not the child seat has been mounted securely.
The vehicular child seat detection system of the first aspect may be modified according to a fifth aspect of the present invention. In this case, the child seat detection means is set opposed to at least one of the left and right fixture attachments for the child seat. The child seat detection means is composed of a striker, moving means and a switch. The striker is attached to the fixture bar. The moving means is pressed toward the striker by urging means and caused to move away from the fixture bar by at least one of the latches. The switch is activated due to a movement of the moving means.
Accordingly, in mounting the child seat to the vehicular seat, if the fixture attachments for the child seat are coupled to the fixture bar, the moving means, which is pressed toward the striker by the urging means, is caused to move away from the fixture bar by at least one of the latches of the fixture attachments. In response to this movement of the moving means, the switch is activated to detect whether or not the child seat has been mounted properly. Thus, with a simple structure, it is possible to detect whether or not the child seat has been mounted securely. In addition, since the fixture attachments for the child seat are designed to be attached to the striker, the overall dimension of the system can be reduced.
In the fifth aspect of the present invention, the moving means may be composed of a slider movably accommodated in the base body attached to the striker. The slider may have an inclined plane for engagement with at least one of the latches.
Furthermore, the vehicular child seat detection system according to the first through fifth aspects of the present invention may also include an indicator indicating, based on a result detected by the child seat detection means, whether or not the child seat has been mounted.
According to this construction, in mounting the child seat to the vehicle, a passenger or an operator can confirm whether or not the child seat has been mounted securely, based on what is indicated by the indicator.
Furthermore, the indicator may be divided into a plurality of display portions, the child seat detection means may detect a plurality of mounting states of the child seat, based on movements of at least one of the latches, and content to be displayed on the display portions are changed in accordance with the plurality of mounting states.
Furthermore, the vehicular child seat detection system according to the first through fifth aspects of the present invention may also include air bag control means for controlling deployment of an air bag depending on whether or not the child seat has been mounted, based on a result detected by the child seat detection means.
Thus, the use of one switch makes it possible to perform air bag control simultaneously with detection of the child seat, depending on whether or not the child seat has been mounted. Therefore, the overall structure of the system can be simplified.